From Sundog to Halo

(Obscure videogame title jokes are us.)

These showed up over Somerville on the afternoon of Saturday the 27th.

Solar halos

Solar halos

Note that you're not seeing a blurred sun here! I was standing just inside the shadow of a building, so the sun was blocked out.

Photo times are 3:41 pm and 3:44 pm, Eastern time, Oct 27 2012. (iPhone 4 camera, nothing special.)

Displays like these are caused by ice crystals in the atmosphere. (Since ice crystals have many flat facets, they can make complex patterns. Raindrops are all round, which is why rainbows are always simple circles.) Apparently this happened across the Northeast as Hurricane Sandy approached.

More commentary and photos from my neighborhood. [Original link to, updated Jan 2022.]

A post-hurricane display in Alabama, same underlying cause. (Photo by David Hathaway.) This is a wider-angle photo which shows all of the bits that I saw (and more clearly).

A friend pointed me at this site diagramming all the things that are going on. There was definitely a circumzenithal arc touching a supralateral -- those are the bright upcurved "rainbow" and the dimmer one touching it. Then there's the upper tangent arc (the birdwing shape). The dark curve touching the bottom of the birdwing is a 22-degree halo. People were talking about a Parry arc, which I think is the brighter upper edge of the birdwing, but I'm not positive.

[Update Jan 2022: Yep, that's the Parry arc. You can also faintly see the Wegener arc in the bottom right corner.]

There was also a parhelic circle, which I didn't try to photograph -- it was a colorless brighter band visible widely left and right of the sun. As in the photo on the linked page, I could see sundogs (rainbow fragments) at two points on the circle.

It was fantastic, and got even more so when I got inside and started figuring out what I'd seen. Thanks to @ywwg for yelling about it and getting me outside.

Update, January 2022

It's been almost ten years, and you may not be surprised to learn that most of the links above are broken. This is embarrassing. For the human race, I mean. How much information is the Information Age losing every month?

As an attempt to halt further degradation, I've tracked down every photo that's still extant from that hurricane halo day in 2012. And I've copied them to this web page. See my total defiance of copyright law! I've linked and attributed each image, but the image data is preserved.

If this web site ever goes down, well, you're probably reading this on the Wayback Machine. Hopefully it snagged everything.

I'll start by including the full-resolution versions of my own two photos:

Solar halos Solar halos
Andrew Plotkin, this page, 2592x1936 versions

The showcase photo, and the one that got the most publicity, is this gorgeous image by David Hathaway in Alabama. I found this on I am happy to say that, as of 2022, that site is still fully functional. (The page now sports a "Time machine" banner, which is a pleasant reminder that somebody cares!)

Solar halos by David Hathaway
David Hathaway/NASA/MSFC via (direct photo link)

It's also worth referring to this annotated version from Imaging Resource:

Solar halos annotated by Imaging Resource
David Hathaway/NASA/MSFC, annotations by Imaging Resource (direct photo link)

The page also mentions photos by Chris Brightwell and Kyle Winkleman. Those links don't work, but Adam Gashlin cleverly tracked them down:

Solar halos by Chris Brightwell Solar halos by Kyle Winkleman
Chris Brightwell and Kyle Winkleman via Project Avalon (direct photo links: image 1, image 2)

Back to Massachusetts -- from Joseph Thiebes in Salem. This one's on Wikimedia. No, I don't really think Wikimedia will go down, but I've got a plan and I'm sticking to it:

Solar halos by Joseph Thiebes
Joseph Thiebes via Wikimedia, CC-BY-SA (direct photo link)

From my own neighborhood, here are a couple that were posted to Livejournal by Freckles42. (The Livejournal thread has since been transferred to Dreamwidth, as noted above.)

Solar halos by Freckles42 Solar halos by Freckles42
Freckles42 via imgur (image 1, image 2)

And one from FiercelyFresh:

Solar halos by FiercelyFresh
FiercelyFresh (direct photo link)

Michael Halle of Universal Hub posted this one over Boylston Street:

Solar halos by Michael Halle
Michael Halle/Universal Hub (Wayback Machine)

A couple from Twitter:

Solar halos by TanyaTerrific
TanyaTerrific on Twitter, Oct 27

Solar halos by robwright11
robwright11 on Twitter, Oct 27

Solar halos by ywwg
ywwg on Twitter, Oct 27 (the tweet that alerted me in the first place!)

-- October 28, 2012

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